The invention relates to fastening elements, used to secure two parts together, and more particularly to three-part fastening elements.
A prior-art three part-fastening element on which this invention improves has a first part or element comprising a sleeve which is slit axially at least once (preferably more) at one of its two ends and is thus radially spreadable at its slit end. This first element has stop regions at each end projecting radially from an approximately uniform cylindrical outer circumferential surface. A second element or part of the three-part fastening element is comprised of a second sleeve which can be introduced into the first sleeve as a spreading mandrel to radially spread the radially spreadable end region of the first sleeve. The second sleeve has a radially projecting collar at its end remote from the spreadable end of the first sleeve. The second element is intended for fastening a first component, by way of the first sleeve, on a wall provided with an opening for receiving the spreadable end of the first sleeve. A third element comprises a cap with a spreading pin extending therefrom that is intended for introduction into the spreading mandrel, which is the second sleeve. The third element is intended for clamping in a second component between the first and second sleeves on one hand, and the cap on the other hand.
The invention is based on the idea of using an existing fastening element as a retaining means for a fastening hook on which parts such as a luggage net in a motor vehicle can be fastened in a releasable manner. This retaining means is intended to be anchored securely in a withdrawal blocking manner.
A three-part fastening element according to this invention has a first part or element comprising a sleeve which is slit axially at least once (preferably more) at one of its two ends and is thus radially spreadable at its slit end. This first element has stop regions at each end projecting radially from an approximately uniform cylindrical outer circumferential surface. A second element or part of the three-part fastening element is comprised of a second sleeve which can be introduced into the first sleeve as a spreading mandrel to radially spread the radially spreadable end region of the first sleeve. The second sleeve has a radially projecting collar at its end remote from the spreadable end of the first sleeve. The second element is intended for fastening a first component, by way of the first sleeve, on a wall provided with an opening for receiving the spreadable end of the first sleeve. A third element comprises a cap with a spreading pin extending therefrom that is intended for introduction into the spreading mandrel, which is the second sleeve. The third element is intended for clamping in a second component between the first and second sleeves on one hand, and the cap on the other hand. The improvement comprises providing the cap with an additional fastening element, preferably, forming a fastening hook integrally on the cap and in that, at its end remote from the cap, the spreading pin is provided with radially spread, elastically deformable spreading tongues in the form of barbs wherein when the spreading pin inserted to the full extent in the first the second sleeves, the barbs project radially out of the first and second sleeves and interact with the first end of the first sleeve in a withdrawal-blocking manner.